To this end, an engine, such as an internal combustion engine, includes a crankshaft sensor and at least one camshaft sensor.
A crankshaft sensor comprises a crankshaft toothed wheel, joined to the crankshaft so as to rotate therewith and comprising a large number of regular teeth and a revolution marker. The crankshaft sensor additionally comprises a crankshaft detector facing said crankshaft toothed wheel and able to detect a presence/absence of material and thus to detect a tooth or a slot (absence of tooth).
The crankshaft toothed wheel is angularly divided equally into a large number of regular teeth, thus making it possible to accurately ascertain the angular position of the crankshaft. The crankshaft toothed wheel additionally comprises a revolution marker allowing an absolute marking of a given angular position, once per revolution. Said revolution marker is generally associated with a particular position of the engine, such as conventionally the top dead center of the first cylinder. Thus, the knowledge of the angular position of the revolution marker indicates precisely the angular position of the engine.
It should be noted that a crankshaft performs two revolutions per cycle of the engine. This results in the angular position of the engine being afflicted by an uncertainty of one revolution out of two.
This uncertainty can be lifted, typically, by using a camshaft sensor, very similar to the crankshaft sensor, but arranged on a camshaft which advantageously performs one revolution per cycle of the engine.
Such a synchronization method may, in a prejudicial manner, be deceived if the engine changes direction of rotation and rotates oppositely. If an engine is considered to be synchronized, whereas it rotates oppositely, a fuel injection can be commanded and can lead to damaging effects for the engine.